Fact: Was it Joram or Jehoram?

Was it Joram or Jehoram? At about the same time, Israel had a king named Joram who was sometimes called Jehoram, while Judah had a king named Jehoram who was sometimes called Joram. King Joram of Israel was a son of Ahab while King Jehoram of Judah married a daughter of Ahab.